RAM is soldered. SSD uses a proprietary connector - fortunately a low cost adapter is now available. Battery is glued to the chassis but there are removal kits

RAM is soldered. SSD uses a proprietary connector - fortunately a low cost adapter is now available. Battery is glued to the chassis but there are removal kits available from iFixit which includes adhesive remover and new adhesive. I've replaced my SSD with a new one using the adapter and it's working perfectly. It's about 2x as fast as the original drive. It's not the best MacBook Pro by any stretch of the imaginative. I've also used a 2016 MBP and 2018 MBP both with Touch Bar and both are far superior. Those were work devices and the 2015 is my personal device which I purchased due to cost. I've been very happy - it's running Catalina Beta perfectly and I've also run Window 10 using Bootcamp and recently have removed that and switched to Parallels running both W7 and W10.